1. Field of the Invention
The present invention relates to a decomposition method of waste plastics, organics, and particularly medical waste composed of various plastics and organics and infectious medical waste, more specifically to a high efficient decomposition method of waste plastics and organics by optimizing respective conditions of decomposition method of waste plastics and organics.
This application claims the priority of Japanese Patent Application No. 2006-297194.
2. Related Background of the Invention
Recently, there have been proposed various methods of treating and recycling waste plastics, and a part thereof are practically employed. As a useful method of recycling and reusing such waste plastics, there is proposed a method and apparatus for gasifying the waste plastics by heating chips of the waste plastics in the presence of a decomposition catalyst of titanium oxide known as a photocatalyst under irradiation of ultraviolet light (Referring to Patent Documents 1, 2).
Further, catalysts used for decomposition treatment of the waste plastics chips have been variously studied (Patent Documents 3 to 5).
The decomposition apparatus using the above decomposition method of waste plastics, however, cannot conduct efficient decomposition treatment of waste plastics, and requires large treatment cost and large apparatus.
Furthermore, the treatment of waste containing polyvinylchloride is known to generate hydrogen chloride gas. Also, the treatment of Teflon is known to generate toxic hydrogen fluoride gas. The treatment of those kinds of gases becomes a problem.
Regarding the prevention of secondary infection caused by infectious medical waste discharged from hospitals, dialysis facilities, and the like, a guideline specifying the treatment method of that kind of waste was issued from the Ministry of Health and Welfare on Nov. 7, 1989, and was enforced on Apr. 1, 1990. The guideline orders the hospitals, dialysis facilities, and the like to conduct in-house or on-site sterilization of the medical waste, in principle.
In this regard, there is wanted the development of a decomposition method for waste plastics, in particular the infectious medical waste containing polyvinylchloride, applicable in hospitals or clinics safely without using large scale apparatus.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2002-363337
[Patent Document 2] Japanese Patent Application Laid-Open No. 2004-182837
[Patent Document 3] Japanese Patent Application Laid-Open No. 2005-066433
[Patent Document 4] Japanese Patent Application Laid-Open No. 2005-205312
[Patent Document 5] Japanese Patent Application Laid-Open No. 2005-307007